This proposal is responsive to the need to further understand social roles among Asian American and Pacific Islander (AAPI) men who have sex with men (MSM) in the U.S. The social construction of sexuality in AAPI cultures does not establish the same dichotomy between heterosexual or homosexual orientation as European-American culture. Thus, AAPI MSM may or may not identify as gay, and may or may not perceive a connection between their sexual behavior and their social role or sexual orientation. The extent to which social roles or perceived sexual orientation are related to stigma, shame, and loss of face among AAPI MSM, and whether these are in turn related to HIV-related risk attitudes and practices is unclear. Moreover, whether the stigma, shame, and loss of face of having sex with men in turn influence use of alcohol, tobacco, and other drugs (ATOD) needs to be explored, as does the relation between ATOD use/abuse and higher risk for HIV in this population. This research is of great significance because, compared to MSM in other racial/ethnic groups, AAPI MSM have the second highest proportion of cumulative AIDS cases (72%) -- only two percentage points lower than white MSM. Proportionately, AAPI MSM (53%) rank second in number of AIDS cases in Year 2000, again after white MSM (62%), (Center for Disease Control and Prevention, 2001). The GWU SPHHS CHSRP, together with the Asian & Pacific Islander Partnership for Health, Washington, DC, therefore, proposes a five-year, two-phase, mixed approach (qualitative and quantitative) study to: 1. Examine socio-cultural forces such as sexual mores, shame, or stigma that play a role in sexual identity and orientation among a cohort of self-identified Chinese, Filipino, and Vietnamese gay/bisexual men and MSM ages 18 and above living in the metropolitan Washington, DC area. 2. Examine the relationship between shame (or stigma) and homosexuality and bisexuality in HIV-related risk attitudes and practices among the cohort of men. 3. Examine the relationship between shame (or stigma) and homosexuality and bisexuality in ATOD use/abuse among the cohort of men. Based on Wong and Edberg's (2001) three-domain, conceptual (i.e., home country background, migration/immigration experience/history, and U.S. experience/situation) model and methodological design, the three (3) Specific Aims will be examined by seven (7) research questions against a selected set of variables.